Durability of Items indicates their condition - how much actions can be performed with them. Each item has two durability parameters, indicated as: current durability/maximum durability (e.g. 3/5).
Current durability[ | ]
An Item with 0 current durability is considered broken and cannot be used. Broken items are indicated in red in the Inventory screen. Current durability does not affect efficiency, though - an 3/5 axe is just as good as 1/3 or 7/7 axes.
Current durability can be increased to maximum durability via Repair action, which can be performed in the Workshop.
It is reduced upon using an item - weapons in combat and hunting, tools in actions like Crafting, woodcutting, Fishing and so on. In construction, a random required tool loses 1 durability on every 50 points of Stamina. Upon Crafting and building, when more than one tool of specific type is available in the village storage, then the one with highest current durability is used and thus it can lose durability.
The difficulty and Stamina cost for Repair and Breakdown of an Item depends on the difference between current and maximum durability. The bigger the difference is, the harder it is to fix an Item. This difficulty is additionally increased greatly if the current durability is 0, so it is a good strategy to use an item only as a last resort, if it has "1" current durability and you are risking to break it.
Maximum durability[ | ]
When maximum durability of an Item drops to 0, it is completely useless and can never be used again.
Maximum durability shows the long-term wear off effect of items. It is lost during Repair - sometimes even if the Repair is successful, it is still reduced - this loss depends on the difficulty of the Repair, the overall skill of the craftsman, as well as on luck.
Maximum durability of an item can never be increased. It has no other in-game effect, other that it limits the current durability.